Zinc oxide nanoparticles: a promising nanomaterial for biomedical applications

Curcuma longa Mediated Synthesis of Copper Oxide, Nickel Oxide and Cu-Ni Bimetallic Hybrid Nanoparticles: Characterization and Evaluation for Antimicrobial, Anti-Parasitic and Cytotoxic Potentials

Nanoparticles have long been known and their biomedical potent activities have proven that these can provide an alternative to other drugs. In the current study, copper oxide, nickel oxide and copper/nickel hybrid NPs were biosynthesized by using Curcuma longa root extracts as a reducing and capping agent, followed by characterization via UV-spectroscopy, Fourier transformed infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo galvanometric analysis (TGA), and band gap. FTIR spectroscopy shows the availability of various functional groups and biomolecules such as carbohydrate, protein, polysaccharides, etc. The EDX peak confirmed that the elemental nickel and copper were present in large quantity in the analyzed sample. Scanning electron micrographs showed that the synthesized CuO-NPs and NiO-NPs were polyhedral uniform and homogeneous in morphology, while the copper/nickel hybrid NPs were well dispersed, spherical in shape, and uniform in size. TEM micrographs of CuO-NPs had 27.72 nm, NiO had 23.13 nm and, for their hybrid, the size was 17.38 nm, which was confirmed respectively. The CuO and NiO NPs possessed spherical- to multi-headed shapes, while their hybrid showed a complete spherical shape, small size, and polydispersed NPs. The XRD spectra revealed that the average particle size for CuO, NiO, and hybrid were 29.7 nm, 28 nm and 27 nm, respectively. Maximum anti-diabetic inhibition of (52.35 ± 0.76: CuO-NPs, 68.1 ± 0.93: NiO-NPs and 74.23 ± 0.42: Cu + Ni hybrids) for α-amylase and (39.25 ± 0.18 CuO-NPs, 52.35 ± 1.32: NiO-NPs and 62.32 ± 0.48: Cu + Ni hybrids) for α-glucosidase were calculated, respectively, at 400 µg/mL. The maximum antioxidants capacity was observed as 65.1 ± 0.83 μgAAE/mg for Cu-Ni hybrids, 58.39 ± 0.62 μgAAE/mg for NiO-NPs, and 52.2 ± 0.31 μgAAE/mg for CuO-NPs, respectively, at 400 μg/mL. The highest antibacterial activity of biosynthesized NPs was observed against P. aeuroginosa (28 ± 1.22) and P. vulgaris (25 ± 1.73) for Cu + Ni hybrids, respectively. Furthermore, the antibiotics were coated with NPs, and activity was noted. Significant anti-leishmanial activity of 60.5 ± 0.53 and 68.4 ± 0.59 for Cu + Ni hybrids; 53.2 ± 0.48 and 61.2 ± 0.44 for NiO-NPs; 49.1 ± 0.39 and 56.2 ± 0.45 for CuO-NPs at 400 μg/mL were recorded for promastigote and amastigotes, respectively. The biosynthesized NPs also showed significant anti-cancerous potential against HepG2 cell lines. It was concluded from the study that NPs are potential agents to be used as an alternative to antimicrobial agents.

Fabrication of Paper Sheets Coatings Based on Chitosan/Bacterial Nanocellulose/ZnO with Enhanced Antibacterial and Mechanical Properties

Here, we designed paper sheets coated with chitosan, bacterial cellulose (nanofibers), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions, with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC® 25922™ following the ASTM E2149-13a standard. The mechanical properties of the paper sheets were measured by comparing tearing resistance, tensile strength, and bursting strength according to the ISO 5270 standard. The results showed an increased antibacterial response (assigned to the combination of chitosan and ZnO, independent of its shape and size) and boosted mechanical properties. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.

Antiprotozoal and anthelmintic activity of zinc oxide nanoparticles

Nanomaterials represent a wide alternative for the treatment of several diseases that affect both human and animal health. The use of these materials mainly involves trying to solve the problem of resistance that pathogenic organisms acquire to conventional drugs. A well-studied example that represents a potential component for biomedical applications is the use of zinc oxide (ZnO) nanoparticles (NPs). Its antimicrobial function is related, especially the ability to generate/induce ROS that affects the homeostasis of the pathogen in question. Protozoa and helminths that harm human health and the economic performance of animals have already been exposed to this type of nanoparticle. Thus, through this review, our goal is to discuss the state-of-the-art effect of ZnO NPs on these parasites.

Ferritinophagy and ferroptosis in cardiovascular disease: Mechanisms and potential applications

Ferroptosis is a type of regulated cell death driven by iron dependent accumulation of cellular reactive oxygen species (ROS) when glutathione (GSH)-dependent lipid peroxidation repair systems are compromised. Nuclear receptor co-activator 4 (NCOA4)-mediated selective autophagy of ferritin, termed ferritinophagy, involves the regulation of ferroptosis. Emerging evidence has revealed that ferritinophagy and ferroptosis exert a significant role in the occurrence and development of cardiovascular disease. In the present review, we aimed to present a brief overview of ferritinophagy and ferroptosis focusing on the underlying mechanism and regulations involved. We summarize and discuss relevant research progress on the role of ferritinophagy and ferroptosis in cardiovascular diseases accompanied with potential applications of ferritinophagy and ferroptosis modulators in the treatment of ferroptosis-associated cardiovascular diseases.

Facile Synthesis of the Cu, N-CDs@GO-CS Hydrogel with Enhanced Antibacterial Activity for Effective Treatment of Wound Infection

Drug resistance and increasing dangers during antibiotic treatment have brought a new eternal task for the research of effective antibacterial agents or therapeutics. In this work, we used Cu, N-doped carbon dots (Cu, N-CDs) to modify graphene oxide (GO) nanosheets and then loaded to chitosan (CS) hydrogels via electrostatic interaction to form Cu, N-CDs@GO-CS hydrogel nanoplatforms to treat Staphylococcus aureus and Escherichia coli. The excellent antibacterial activity is from the combined effects of hyperthermia and reactive oxygen species generated under near-infrared (NIR) laser irradiation of the Cu, N-CDs@GO-CS hydrogel, which shows excellent antibacterial activity compared with the CS hydrogel or the Cu, N-CDs@GO-CS hydrogel without NIR laser irradiation. Moreover, the inherent antibacterial nature of the CS hydrogel or the Cu, N-CDs@GO-CS hydrogel was used to treat bacteria-infected wounds in mice, which also protected the wound area from second infection. In vivo experiments demonstrate favorable wound healing results and have no significant harmful side effects to the major organs in mice. Overall, this work demonstrates that the antibacterial Cu, N-CDs@GO-CS hydrogel offers significant prospect as an antibacterial reagent for wound healing.

Use of nanotechnology in combating coronavirus

Recent COVID-19 pandemic situation caused due to the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affected global health as well as economics. There is global attention on prevention, diagnosis as well as treatment of COVID-19 infection which would help in easing the current situation. The use of nanotechnology and nanomedicine has been considered to be promising due to its excellent potential in managing various medical issues such as viruses which is a major threat. Nanoparticles have shown great potential in various biomedical applications and can prove to be of great use in antiviral therapy, especially over other conventional antiviral agents. This review focusses on the pathophysiology of SARS-CoV-2 and the progression of the COVID-19 disease followed by currently available treatments for the same. Use of nanotechnology has been elaborated by exploiting various nanoparticles like metal and metal oxide nanoparticles, carbon-based nanoparticles, quantum dots, polymeric nanoparticles as well as lipid-based nanoparticles along with its mechanism of action against viruses which can prove to be beneficial in COVID-19 therapeutics. However, it needs to be considered that use of these nanotechnology-based approaches in COVID-19 therapeutics only aids the human immunity in fighting the infection. The main function is performed by the immune system in combatting any infection.

Zinc oxide nanoparticles from Cassia auriculata flowers showed the potent antimicrobial and in vitro anticancer activity against the osteosarcoma MG-63 cells

Osteosarcoma (OS) is a foremost mesenchymal bone neoplasm and it can occur at any age with survival rate is nearly 2-8 times lesser in elders than in teenagers. The clinical therapies for cancer treatment have gradually becoming outdated because of the developments of nano-medicine and multi-targeted drug-delivery. In this work, we green synthesized the zinc oxide nanoparticles from the Cassia auriculata flower (AS-ZnONPs) extract and evaluated its antimicrobial and in vitro anticancer potential against the OS MG-63 cells. The synthesized AS-ZnONPs were confirmed and characterized by using UV-vis spectroscopy, XRD, FE-SEM, and photoluminescence techniques. The antimicrobial activity of AS-ZnONPs was studied by disc diffusion technique. The viability of AS-ZnONPs treated MG-63 cells were examined by MTT assay. The apoptotic cells in the AS-ZnONPs treated MG-63 cells were assayed by dual staining. The MMP status of AS-ZnONPs treated cells were tested by Rh-123 staining. The cell adhesion assay was performed to detect the anticancer effects of AS-ZnONPs against MG-63 cells. The results of UV-vis spectroscopy, XRD, FE-SEM, and photoluminescence techniques proved the formation of AS-ZnONPs and it has the hexagonal wurtzite structures. AS-ZnONPs displayed the potent antimicrobial activity against the tested microbial strains. The AS-ZnONPs were appreciably inhibited the cell viability of MG-63 cells. The outcomes of fluorescence staining proved that AS-ZnONPs reduced the MMP and prompted the apoptosis in MG-63 cells. In conclusion, our discoveries demonstrated that the formulated AS-ZnONPs has the potent antimicrobial and in vitro anticancer activity against the MG-63 cells. The AS-ZnONPs could be potent chemotherapeutic agent in the future to treat the OS.

Electrospun Nanosystems Based on PHBV and ZnO for Ecological Food Packaging

The electrospun nanosystems containing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and 1 wt% Fe doped ZnO nanoparticles (NPs) (with the content of dopant in the range of 0–1 wt% Fe) deposited onto polylactic acid (PLA) film were prepared for food packaging application. They were investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), antimicrobial analysis, and X-ray photoelectron spectrometry (XPS) techniques. Migration studies conducted in acetic acid 3% (wt/wt) and ethanol 10% (v/v) food simulants as well as by the use of treated ashes with 3% HNO₃ solution reveal that the migration of Zn and Fe falls into the specific limits imposed by the legislation in force. Results indicated that the PLA/PHBV/ZnO:Fex electrospun nanosystems exhibit excellent antibacterial activity against the Pseudomonas aeruginosa (ATCC-27853) due to the generation of a larger amount of perhydroxyl (˙OOH) radicals as assessed using electron paramagnetic resonance (EPR) spectroscopy coupled with a spin trapping method.

Protective Effect of Zinc Oxide and Its Association with Neutrophil Degranulation in Piglets Infected with Porcine Epidemic Diarrhea Virus

Porcine epidemic diarrhea virus (PEDV) has reemerged throughout the world in the past ten years and caused huge economic losses to the swine industry. No drugs are available to prevent or treat PEDV infection in piglets. Zinc oxide (ZnO) has been shown to reduce diarrhea. However, little is known about its role in PEDV infection. In this study, twenty-four 7-day-old piglets were randomly divided into three treatment groups: control, PEDV, and ZnO+PEDV. Piglets in the ZnO+PEDV group were orally administered with 100 mg/kg·BW ZnO and then inoculated PEDV at a dose of 10^4.5 TCID₅₀ (50% tissue culture infectious dose) per pig. Growth performance, histologic lesions, viral load, indicators of intestinal damage, inflammation, and oxidative stress were recorded or detected to determine the effect of ZnO on PEDV infection. And the underlying mechanisms were revealed by microarray and proteomic analyses. Results showed that ZnO administration mitigated diarrhea and the reduction of average daily weight gain induced by PEDV infection. ZnO could inhibit PEDV replication in the small intestine and colon. Both villus height and crypt depth were affected by PEDV infection in the duodenum and jejunum, which could be rescued by ZnO administration. Moreover, the activity of catalase was decreased both in plasma and intestine after PEDV infection, while increased in the intestine by ZnO administration. PEDV infection also significantly increased the concentration of H₂O₂ in jejunal and ileum and decreased the activity of total superoxide dismutase and glutathione peroxidase in plasma, whereas ZnO administration obviously increased the activity of total superoxide dismutase and decreased the concentration of H₂O₂ in the ileum. The concentrations of IL-1β, IL-6, and IL-8 in the plasma were all decreased upon ZnO administration. A large number of differentially expressed genes and proteins were identified in the ileum among the three groups by microarray and proteomic analyses. Gene Ontology and Reactome pathway analyses indicated that neutrophil degranulation and nutrient metabolism were the main biological process and pathways in both PEDV infection and ZnO administration. Overall, ZnO administration could improve growth performance, intestinal redox status, morphology, and function and reduce diarrhea in PEDV-infected piglets; ZnO could exert antiviral and anti-inflammatory effects on PEDV-infected piglets probably through regulating neutrophil degranulation. Our findings have important implications in piglet and infant nutrition.

Antiviral Nanomaterials for Designing Mixed Matrix Membranes

Membranes are helpful tools to prevent airborne and waterborne pathogenic microorganisms, including viruses and bacteria. A membrane filter can physically separate pathogens from air or water. Moreover, incorporating antiviral and antibacterial nanoparticles into the matrix of membrane filters can render composite structures capable of killing pathogenic viruses and bacteria. Such membranes incorporated with antiviral and antibacterial nanoparticles have a great potential for being applied in various application scenarios. Therefore, in this perspective article, we attempt to explore the fundamental mechanisms and recent progress of designing antiviral membrane filters, challenges to be addressed, and outlook.

Zinc Oxide Nanoparticles Can Intervene in Radiation-Induced Senescence and Eradicate Residual Tumor Cells

Despite recent advancements in tumor therapy, metastasis and tumor relapse remain major complications hindering the complete recovery of many cancer patients. Dormant tumor cells, which reside in the body, possess the ability to re-enter the cell cycle after therapy. This phenomenon has been attributed to therapy-induced senescence. We show that these cells could be targeted by the use of zinc oxide nanoparticles (ZnO NPs). In the present study, the properties of tumor cells after survival of 16 Gy gamma-irradiation were investigated in detail. Analysis of morphological features, proliferation, cell cycle distribution, and protein expression revealed classical hallmarks of senescent cells among the remnant cell mass after irradiation. The observed radiation-induced senescence was associated with the increased ability to withstand further irradiation. Additionally, tumor cells were able to re-enter the cell cycle and proliferate again after weeks. Treatment with ZnO NPs was evaluated as a therapeutical approach to target senescent cells. ZnO NPs were suitable to induce cell death in senescent, irradiation-resistant tumor cells. Our findings underline the pathophysiological relevance of remnant tumor cells that survived first-line radiotherapy. Additionally, we highlight the therapeutic potential of ZnO NPs for targeting senescent tumor cells.

Fluorescence coupled capillary electrophoresis as a strategy for tetrahedron DNA analysis

A strategy based on fluorescence coupled capillary electrophoresis (CE-FL) was developed for analyzing tetrahedron DNA (TD) and TD-doxorubicin (DOX) conjugate. Capillary gel electrophoresis exhibited desirable performance for separating TD and DNA strands. Under the optimized conditions, satisfactory repeatability concerning run-to-run and interday repeatability was obtained, and relative standard deviation value of resolution (n = 6) was 0.64%. Furthermore, the combination of CE and fluorescence detection provided a sensitive platform for quantifying TD concentration and calculating the damage degree of TD. The electrophoretograms indicated that CE-FL was a suitable TD assay method with high specificity and sensitivity. In addition, the application of CE-FL for TD fluorescence resonance energy transfer (FRET) research was also explored. Two types of DNA strands were utilized to interfere the formation of TD. The impact of partially complementary chain and completely complementary chain on FRET signal was explored, and the influence mechanism was discussed. After applying CE-FL for characterizing TD, we also combine CE and FRET to analyze TD-DOX conjugate. CE presented a favourable technique to monitor DOX loading and releasing processes. These noteworthy results offered a stepping stone for DNA nanomaterials assay by using CE-FL.

Saussurea lappa plant rhizome extract-based zinc oxide nanoparticles: synthesis, characterization and its antibacterial, antifungal activities and cytotoxic studies against Chinese Hamster Ovary (CHO) cell lines

The plant extracts are known for their anti-inflammatory, antifungal, antiviral and antibacterial properties. The use of plant extracts in the preparation of bio-materials increases their biological application. In this concern, herein reporting an eco-friendly procedure which is also a simple and cost effective, for the synthesis of Zinc Oxide nanoparticles (ZnONPs) using Saussurea lappa plant root (rhizome) extract as a fuel. The prepared nanoparticles were confirmed using various characterization techniques. The Dynamic light scattering data showed 123.5 nm particle size with -99.9 mv zeta potential which indicates excellent stability of the particles. The peak at 541 cm-1 in the IR spectrum is assigned to the stretching frequency of the zinc-binding to oxygen. The X-ray diffraction peaks confirm the close association with JCPDS Data Card No: 36-1451. The FESEM data revealed a hexagonal wurtzite structure with a hexagonal shape of synthesized ZnO nanoparticles. The antibacterial studies indicate the gram-negative strains showed better inhibition activity than gram-positive strains. Among Fungal strains, Aspergillus niger and flavus, Fusarium oxysporum, and Rhizopus oryzae showed good inhibition activity at higher concentrations. The cytotoxic data indicates the 5 μg/mL of the ZnO particles showed cytotoxicity on the CHO cell line and with IC50 value 3.164 ± 0.8956 μg/mL.

Antimicrobial Effect of Chitosan Films on Food Spoilage Bacteria

Synthetic materials commonly used in the packaging industry generate a considerable amount of waste each year. Chitosan is a promising feedstock for the production of functional biomaterials. From a biological point of view, chitosan is very attractive for food packaging. The purposes of this study were to evaluate the antibacterial activity of a set of chitosan-metal oxide films and different chitosan-modified graphene (oxide) films against two foodborne pathogens: Campylobacter jejuni ATCC 33560 and Listeria monocytogenes 19115. Moreover, we wanted to check whether the incorporation of antimicrobial constituents such as TiO2, ZnO, Fe2O3, Ag, and graphene oxide (GO) into the polymer matrices can improve the antibacterial properties of these nanocomposite films. Finally, this research helps elucidate the interactions of these materials with eukaryotic cells. All chitosan-metal oxide films and chitosan-modified graphene (oxide) films displayed improved antibacterial (C. jejuni ATCC 33560 and L. monocytogenes 19115) properties compared to native chitosan films. The CS-ZnO films had excellent antibacterial activity towards L. monocytogenes (90% growth inhibition). Moreover, graphene-based chitosan films caused high inhibition of both tested strains. Chitosan films with graphene (GO, GOP, GOP-HMDS, rGO, GO-HMDS, rGOP), titanium dioxide (CS-TiO2 20:1a, CS-TiO2 20:1b, CS-TiO2 2:1, CS-TiO2 1:1a, CS-TiO2 1:1b) and zinc oxide (CS-ZnO 20:1a, CS-ZnO 20:1b) may be considered as a safe, non-cytotoxic packaging materials in the future.

Recent trends on burn wound care: hydrogel dressings and scaffolds

Acute and chronic wounds can cause severe physical trauma to patients and also result in an immense socio-economic burden. Thus, wound management has attracted increasing attention in recent years. However, burn wound management is still a major challenge in wound management. Autografts are often considered the gold-standard for burn care, but their application is limited by many factors. Hence, ideal burn dressings and skin substitute dressings are desirable. With the development of biomaterials and progress of tissue engineering technology, some innovative dressings and tissue engineering scaffolds, such as nanofibers, films, foams and hydrogels, have been widely used in the field of biomedicine, especially in wound management. Among them, hydrogels have attracted tremendous attention with their unique advantages. In this review, we discuss the challenges in burn wound management, several crucial design considerations with respect to hydrogels for burn wound healing, and available polymers for hydrogels in burn wound care. In addition, the potential application and plausible prospect of hydrogels are also highlighted.

Prediction of Skin Sensitization Potential of Silver and Zinc Oxide Nanoparticles Through the Human Cell Line Activation Test

The development of nanotechnology has propagated the use of nanoparticles (NPs) in various fields including industry, agriculture, engineering, cosmetics, or medicine. The use of nanoparticles in cosmetics and dermal-based products is increasing owing to their higher surface area and unique physiochemical properties. Silver (Ag) NPs' excellent broad-spectrum antibacterial property and zinc oxide (ZnO) NPs' ability to confer better ultraviolet (UV) protection has led to their maximal use in cosmetics and dermal products. While the consideration for use of nanoparticles is increasing, concerns have been raised regarding their potential negative impacts. Although used in various dermal products, Ag and ZnO NPs' skin sensitization (SS) potential has not been well-investigated using in vitro alternative test methods. The human Cell Line Activation Test (h-CLAT) that evaluates the ability of chemicals to upregulate the expression of CD86 and CD54 in THP-1 cell line was used to assess the skin sensitizing potential of these NPs. The h-CLAT assay was conducted following OECD TG 442E. NPs inducing relative fluorescence intensity of CD86 ≥ 150% and/or CD54 ≥ 200% in at least two out of three independent runs were predicted to be positive. Thus, Ag (20, 50, and 80 nm) NPs and ZnO NPs were all predicted to be positive in terms of SS possibility using the h-CLAT prediction model. Although further confirmatory tests addressing other key events (KEs) of SS adverse outcome pathway (AOP) should be carried out, this study gave an insight into the need for cautious use of Ag and ZnO NPs based skincare or dermal products owing to their probable skin sensitizing potency.

Antimicrobial PAA/PAH Electrospun Fiber Containing Green Synthesized Zinc Oxide Nanoparticles for Wound Healing

Wound infections are the main complication when treating skin wounds. This work reports a novel antimicrobial material using green synthesized zinc oxide nanoparticles (ZnONPs) incorporated in polymeric fibers for wound healing purposes. ZnONPs are a promising antimicrobial nanomaterial with high activity against a range of microorganisms, including drug-resistant bacteria. The electrospun fibers were obtained using polyacrylic acid (PAA) and polyallylamine hydrochloride (PAH) and were loaded with ZnONPs green synthesized from Ilex paraguariensis leaves with a spherical shape and ~18 nm diameter size. The fibers were produced using the electrospinning technique and SEM images showed a uniform morphology with a diameter of ~230 nm. EDS analysis proved a consistent dispersion of Zn in the fiber mat, however, particle agglomerates with varying sizes were observed. FTIR spectra confirmed the interaction of PAA carboxylic groups with the amine of PAH molecules. Although ZnONPs presented higher antimicrobial activity against S. aureus than E. coli, resazurin viability assay revealed that the PAA/PAH/ZnONPs composite successfully inhibited both bacteria strains growth. Photomicrographs support these results where bacteria clusters were observed only in the control samples. The PAA/PAH/ZnONPs composite developed presents antimicrobial activity and mimics the extracellular matrix morphology of skin tissue, showing potential for wound healing treatments.

Green-synthesized zinc oxide nanoparticles, anti-Alzheimer potential and the metabolic profiling of Sabal blackburniana grown in Egypt supported by molecular modelling

Nowadays, the biosynthesis of metal nanoparticles, particularly from plants, has been gaining interest. In the present work, the methanolic extracts of leaves, fruits, and the pollen grains of Sabal blackburniana were used for the green synthesis of ZnO nanoparticles, which were early detected by the formation of precipitate and further confirmed by UV-vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy and zeta potential (ZP) studies. TEM analysis has shown different shapes, predominantly irregular small spherical narrow particles included in hexagonal structures with size ranging from 2.23 to 49.56 nm. The XRD pattern confirmed that all synthesized ZnO nanoparticles have wurtzite hexagonal structure with crystalline nature. The average particle crystallite sizes were 47.21, 47.67 and 47.8 nm. The UV-visible spectra showed λ max in the range of 354-368 nm, which indicated the presence of ZnO nanoparticles. The FT-IR analysis identifies the characteristic functional groups present on the surface of ZnO nanoparticles. The ZP determination demonstrated that all representative selected synthesized ZnONPs exhibited acceptable ZP values of -30.8 to -45.9 mV, which indicated their good stability. In addition, the anti-Alzheimer potential of the selected extracts and ZnONPs was evaluated by assessing acetylcholinesterase inhibitory activity in vitro according to the improved Ellman method. The results indicated that the selected extracts have acetylcholinesterase inhibitory activity, and highlighted the promising inhibitory potential of green-synthesized ZnONPs using pollen grains, fruits and leaves extracts; they exhibited a potent inhibitory effect with IC50 values 63.78 ± 1.04651, 81.985 ± 3.075 and 117.95 ± 6.858 ng ml-1 respectively in comparison to donepezil as standard (IC50 = 50.7 ± 5.769 ng ml-1). Dereplication analysis of the selected extracts was performed using LC-MS; metabolic profiling revealed the presence of 41 compounds belonging to various chemical classes: flavonoids, steroidal saponins, terpenoids, alkaloids, lignans, sterols and fatty acids. Docking these dereplicated metabolites against the human AChE showed that the non-glycosylated flavonoid class of compounds was able to achieve interesting binding modes inside the AChE active site; they are suggested to be associated with the observed anti-AChE activity of Sabal extracts. This study is the first report to shed light on the acetylcholinesterase inhibitory activity of green-synthesized ZnO nanoparticles of S. blackburniana metabolites.

Stabilization of Nrf2 leading to HO-1 activation protects against zinc oxide nanoparticles-induced endothelial cell death

With the abundant production and wide application of zinc oxide nanoparticles (ZnONPs), the potential health risks of ZnONPs have raised serious concerns. Oxidative stress is recognized as the most important outcome of the toxicity induced by ZnONPs. The Nrf2-Keap1 system and its downstream antioxidative genes are the fundamental protective mechanisms for redox hemeostasis. However, the detailed mechanisms of Nrf2 activation in ZnONPs-treated endothelial cells and murine blood vessels have yet to be elucidated. Herein, we show that Nrf2 was activated and played a negative role in cell death induced by ZnONPs. Moreover, we demonstrate that HO-1 was the most extensively upregulated antioxidative gene-activated by Nrf2. Forced overexpression of HO-1, pharmacological activation of HO-1 with the agonists RTA-408 (omaveloxolone, an FDA-approved drug) and RTA-402 repressed cell death, and treatment with HO-1 antagonist SnPP exacerbated the cell death. Importantly, loss of HO-1 diminished the cytoprotective role induced by Nrf2 in ZnONPs-treated HUVEC cells, indicating that the Nrf2-HO-1 axis was the crucial regulatory mechanism for the antioxidative response in the context of ZnONPs-induced endothelial damage. Mechanistically, we demonstrate that the p62-Keap1 axis was not involved in the activation of Nrf2. Intriguingly, the degradation half-life of Nrf2 in HUVEC cells was increased from less than 1 h under quiescent conditions to approximately 6 h under ZnONPs treatment condition; moreover, ZnONPs treatment induced activation of Nrf2/HO-1 and accumulation of ubiquitin in the aorta ventralis of mouse, suggesting that the ubiquitin-proteasome system had been perturbed, which subsequently led to the stabilization of Nrf2 and activation of HO-1. This study might contribute to a better understanding of ZnONPs-associated toxicity.

Nanotechnology Approaches in Chronic Wound Healing

Significance: The incidence of chronic wounds is increasing due to our aging population and the augment of people afflicted with diabetes. With the extended knowledge on the biological mechanisms underlying these diseases, there is a novel influx of medical technologies into the conventional wound care market. Recent Advances: Several nanotechnologies have been developed demonstrating unique characteristics that address specific problems related to wound repair mechanisms. In this review, we focus on the most recently developed nanotechnology-based therapeutic agents and evaluate the efficacy of each treatment in in vivo diabetic models of chronic wound healing. Critical Issues: Despite the development of potential biomaterials and nanotechnology-based applications for wound healing, this scientific knowledge is not translated into an increase of commercially available wound healing products containing nanomaterials. Future Directions: Further studies are critical to provide insights into how scientific evidences from nanotechnology-based therapies can be applied in the clinical setting.

Towards a microfluidics platform for the continuous manufacture of organic and inorganic nanoparticles

In the last decade, microfluidics has opened new avenues for the synthesis of nanomaterials. However, the adoption of this production technique has been limited to a few high-value, low-production-volume organic nanoparticles. While there are several technical factors that can be attributed to this slow adoption, an important aspect to consider is the lack of a unified platform capable of producing a wide range of nanomaterials. In this work, we highlight a micro-mixing platform that can manufacture both organic and in-organic nanoparticles over a wide size range (nm-μm). We show that the platform can predictably and reproducibly create size and shape-controlled formulations with high homogeneity through input flow parameters. We further explore parallelization of this platform and discuss key technical constraints for high-volume production. We believe that the platform presented in this work can accelerate the adoption of nanomaterials relevant to a range of industries that encompass pharmaceutics, diagnostics, and cosmeceuticals.

Facile green synthesis of ZnO-RGO nanocomposites with enhanced anticancer efficacy

Drug resistance and inability to distinguish between cancerous and non-cancerous cells are important obstacles in the treatment of cancer. Zinc oxide nanoparticles (ZnO NPs) is now emerging as a crucial material to challenge this global issue due to its tunable properties. Developing an effective, inexpensive, and eco-friendly method in order to tailor the properties of ZnO NPs with enhanced anticancer efficacy is still challenging. For the first time, we reported a facile, inexpensive, and eco-friendly approach for green synthesis of ZnO-reduced graphene oxide nanocomposites (ZnO-RGO NCs) using garlic clove extract. Garlic has been playing one of the most important dietary and medicinal roles for humans since centuries. We aimed to minimize the use of toxic chemicals and enhance the anticancer potential of ZnO-RGO NCs with minimum side effects to normal cells. Aqueous extract of garlic clove was used as reducing and stabilizing agent for green synthesis of ZnO-RGO NCs from the zinc nitrate and graphene oxide (GO) precursors. A potential mechanism of ZnO-RGO NCs synthesis with garlic clove extract was also proposed. Preparation of pure ZnO NPs and ZnO-RGO NCs was confirmed by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and dynamic light scattering (DLS). The in vitro study showed that ZnO-RGO NCs induce two-fold higher cytotoxicity in human breast cancer (MCF7) and human colorectal cancer (HCT116) cells as compared to pure ZnO NPs. Besides, biocompatibility of ZnO-RGO NCs in non-cancerous human normal breast (MCF10A) and normal colon epithelial (NCM460) cells was higher than those of pure ZnO NPs. This work highlighted a facile and inexpensive green approach for the preparation of ZnO-RGO NCs with enhanced anticancer activity and improved biocompatibility.

Dose-Dependent Effect of ZnO Quantum Dots for Lettuce Growth

As the cadmium-free semiconductor quantum dots, ZnO quantum dots (ZnO QDs) have wide potential applications in agriculture. However, the effects of ZnO quantum dots on crop growth and nutritional quality have not been fully studied. In this work, the lettuce was sprayed with different concentrations of ZnO QDs from 50 to 500 mg·L^-1 to evaluate their influence on lettuce antioxidant, biomass, and nutritional quality. The results showed that ZnO QDs existed in the lettuce in the form of Zn²⁺. Lettuce treated with 500 mg·L^-1 ZnO QDs would produce a large amount of reactive oxygen species (ROS), which adversely affected the absorption of nutrients, soluble protein content, and chlorophyll content, thus reducing plant biomass. When the concentrations range from 50 to 200 mg·L^-1, the antioxidant enzyme systems of lettuce were triggered to counteract the damage caused by excessive ROS. Moreover, ZnO QDs at this level promoted Ca, Mg, Fe, Mn, Zn, and B absorption and accumulation; increased soluble sugar content; and improved the lettuce biomass and nutritional quality.

Synthesis and modification of bio-derived antibacterial Ag and ZnO nanoparticles by plants, fungi, and bacteria

Ag and ZnO nanoparticles (NP) can be prepared by physical, chemical, or eco-friendly methods. The biosynthesis of metal and metal oxide NPs by plants, fungi, and bacteria could be a promising way to obtain biocompatible NPs that have desirable antibacterial activities. However, the uniformity of shape, size, and size distribution of NPs are crucial to producing significant antibacterial results, particularly in physiological conditions such as infected wounds or septicemia. In this review, we discuss recent progress and challenges in the use of novel approaches for the biosynthesis of Ag and ZnO nanoparticles that have antibacterial activities.

Green Synthesis of Zinc Oxide (ZnO) Nanoparticles Using Aqueous Fruit Extracts of Myristica fragrans: Their Characterizations and Biological and Environmental Applications

In the present work, bioaugmented zinc oxide nanoparticles (ZnO-NPs) were prepared from aqueous fruit extracts of Myristica fragrans. The ZnO-NPs were characterized by different techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and thermogravimetric analysis (TGA). The crystallites exhibited a mean size of 41.23 nm measured via XRD and were highly pure, while SEM and TEM analyses of synthesized NPs confirmed their spherical or elliptical shape. The functional groups responsible for stabilizing and capping of ZnO-NPs were confirmed using FTIR analysis. The ζ-size and ζ-potential of synthesized ZnO-NPs were reported as 66 nm and -22.1 mV, respectively, via the DLS technique can be considered as moderate stable colloidal solution. Synthesized NPs were used to evaluate for their possible antibacterial, antidiabetic, antioxidant, antiparasitic, and larvicidal properties. The NPs were found to be highly active against bacterial strains both coated with antibiotics and alone. Klebsiella pneumoniae was found to be the most sensitive strain against NPs (27 ± 1.73) and against NPs coated with imipinem (26 ± 1.5). ZnO-NPs displayed outstanding inhibitory potential against enzymes protein kinase (12.23 ± 0.42), α-amylase (73.23 ± 0.42), and α-glucosidase (65.21 ± 0.49). Overall, the synthesized NPs have shown significant larvicidal activity (77.3 ± 1.8) against Aedes aegypti, the mosquitoes involved in the transmission of dengue fever. Similarly, tremendous leishmanicidal activity was also observed against both the promastigote (71.50 ± 0.70) and amastigote (61.41 ± 0.71) forms of the parasite. The biosynthesized NPs were found to be excellent antioxidant and biocompatible nanomaterials. Biosynthesized ZnO-NPs were also used as photocatalytic agents, resulting in 88% degradation of methylene blue dye in 140 min. Owing to their eco-friendly synthesis, nontoxicity, and biocompatible nature, ZnO-NPs synthesized from M. fragrans can be exploited as potential candidates for biomedical and environmental applications.

Ferritinophagy is involved in the zinc oxide nanoparticles-induced ferroptosis of vascular endothelial cells

Zinc oxide nanoparticles (ZnONPs) hold great promise for biomedical applications. Previous studies have revealed that ZnONPs exposure can induce toxicity in endothelial cells, but the underlying mechanisms have not been fully elucidated. In this study, we report that ZnONPs can induce ferroptosis of both HUVECs and EA.hy926 cells, as evidenced by the elevation of intracellular iron levels, lipid peroxidation and cell death in a dose- and time-dependent manner. In addition, both the lipid reactive oxygen species (ROS) scavenger ferrostatin-1 and the iron chelator deferiprone attenuated ZnONPs-induced cell death. Intriguingly, we found that ZnONPs-induced ferroptosis is macroautophagy/autophagy-dependent, because the inhibition of autophagy with a pharmacological inhibitor or by ATG5 gene knockout profoundly mitigated ZnONPs-induced ferroptosis. We further demonstrated that NCOA4 (nuclear receptor coactivator 4)-mediated ferritinophagy (autophagic degradation of the major intracellular iron storage protein ferritin) was required for the ferroptosis induced by ZnONPs, by showing that NCOA4 knockdown can reduce the intracellular iron level and lipid peroxidation, and subsequently alleviate ZnONPs-induced cell death. Furthermore, we showed that ROS originating from mitochondria (mtROS) probably activated the AMPK-ULK1 axis to trigger ferritinophagy. Most importantly, pulmonary ZnONPs exposure caused vascular inflammation and ferritinophagy in mice, and ferrostatin-1 supplementation significantly reversed the vascular injury induced by pulmonary ZnONPs exposure. Overall, our study indicates that ferroptosis is a novel mechanism for ZnONPs-induced endothelial cytotoxicity, and that NCOA4-mediated ferritinophagy is required for ZnONPs-induced ferroptotic cell death.

Photocatalytic Behaviour of Zinc Oxide Nanostructures on Surface Activation of Polymeric Fibres

Zinc oxide (ZnO) in various nano forms (nanoparticles, nanorods, nanosheets, nanowires and nanoflowers) has received remarkable attention worldwide for its functional diversity in different fields i.e., paints, cosmetics, coatings, rubber and composites. The purpose of this article is to investigate the role of photocatalytic activity (role of photogenerated radical scavengers) of nano ZnO (nZnO) for the surface activation of polymeric natural fibres especially cotton and their combined effect in photocatalytic applications. Photocatalytic behaviour is a crucial property that enables nZnO as a potential and competitive candidate for commercial applications. The confirmed features of nZnO were characterised by different analytical tools, i.e., scanning electron microscopy (SEM), field emission SEM (FESEM) and elemental detection spectroscopy (EDX). These techniques confirm the size, morphology, structure, crystallinity, shape and dimensions of nZnO. The morphology and size play a crucial role in surface activation of polymeric fibres. In addition, synthesis methods, variables and some of the critical aspects of nZnO that significantly affect the photocatalytic activity are also discussed in detail. This paper delineates a vivid picture to new comers about the significance of nZnO in photocatalytic applications.

Broiler welfare is preserved by long-term low-dose oral exposure to zinc oxide nanoparticles: preliminary study

The potential public health risk through utilizing of zinc oxide nanoparticles (ZnO NPs) in food constitutes the major obstacle to the expansion of nanoparticle (NP) in food industry. Liver histology, bone marrow and liver genotoxicity, immunity, and oxidant status were investigated upon long-term ZnO NPs feed supplementation. One hundred and sixty male IR (Indian River) chicks were randomly allocated to one of the four dietary treatments: control, ZnO NPs at 10, 20, or 40 mg/kg for 42 days. This study revealed non-significant hepatic histopathological alterations and DNA damage and the treatment had no influence on body and organ weights, liver enzymes, lipid peroxidation (MDA), IgG, IgM, and interferon gamma (IFN-γ). This study suggests that low-dose (< 40 mg/kg diet) long-term ZnO NPs supplementation to broiler chicks has no observed potential adverse effects on normal histology of the liver, blood physiology, immune system, and DNA damage of liver and bone marrows, which are critical features for validating ZnO NPs for use in food. Further studies are required to evaluate the probable withdrawal period of ZnO NPs before approval as a dietary supplement in broiler or livestock diets.

Utilizing of (Zinc Oxide Nano-Spray) for Disinfection against “SARS-CoV-2” and Testing Its Biological Effectiveness on Some Biochemical Parameters during (COVID-19 Pandemic)—”ZnO Nanoparticles Have Antiviral Activity against (SARS-CoV-2)”

A newly synthesized zinc (II) oxide nanoparticle (ZnO-NPs) has been used as a disinfectant Nano-spray for the emerging corona virus (SARS-CoV-2). The synthesized obtained nanomaterial of (ZnO) was fully chemically characterized by using different spectroscopic analysis (FT-IR, UV and XRD) and surface analysis techniques. ZnO-Nps surface morphology and chemical purity has been investigated by transmission electron microscope (TEM), high resolution transmission electron microscope (HR-TEM), scanning electron microscopy (SEM) as well as energy dispersive X-ray analysis (EDX), Additionally Zeta potential and Zeta size distribution were measured and evaluated to confirm its nano-range scale. The synthesized Zno-NPs have been tested using 10% DMSO and ddH2O for estimation of antiviral activity against (SARS-CoV-2) by using cytotoxicity assay (CC50) and inhibitory concentration (IC50). The results revealed that (Zno-NPs) has high anti-SARS-CoV-2 activity at cytotoxic concentrations in vitro with non-significant selectivity index (CC50/IC50 ≤ 1). The current study results demonstrated the (ZnO-NPs) has potent antiviral activity at low concentration (IC50 = 526 ng/mL) but with some cytotoxic effect to the cell host by (CC50 = 292.2 ng/mL). We recommend using of (ZnO-NPs) as potent disinfectant against (SARS-Cov-2), but there are slight side effects on the cellular host, so we recommend more prospective studies on complexation of other compounds with (ZnO-NPs) in different concentrations to reduce its cellular toxicity and elevate its antiviral activity against SARS-CoV-2 activities.

Investigating the Internalization and COVID-19 Antiviral Computational Analysis of Optimized Nanoscale Zinc Oxide

Global trials are grappling toward identifying prosperous remediation against the ever-emerging and re-emerging pathogenic respiratory viruses. Battling coronavirus, as a model respiratory virus, via repurposing existing therapeutic agents could be a welcome move. Motivated by its well-demonstrated curative use in herpes simplex and influenza viruses, utilization of the nanoscale zinc oxide (ZnO) would be an auspicious approach. In this direction, ZnO nanoparticles (NPs) were fabricated herein and relevant aspects related to the formulation such as optimization, structure, purity, and morphology were elucidated. In silico molecular docking was conducted to speculate the possible interaction between ZnO NPs and COVID-19 targets including the ACE2 receptor, COVID-19 RNA-dependent RNA polymerase, and main protease. The cellular internalization of ZnO NPs using human lung fibroblast cells was also assessed. Optimized hexagonal and spherical ZnO nanostructures of a crystallite size of 11.50 ± 0.71 nm and positive charge were attained. The pure and characteristic hexagonal wurtzite P63mc crystal structure was also observed. Interestingly, felicitous binding of ZnO NPs with the three tested COVID-19 targets, via hydrogen bond formation, was detected. Furthermore, an enhanced dose-dependent cellular uptake was demonstrated. The obtained results infer a rationale, awaiting validation from further biological and therapeutic studies.

Effectiveness and safety of zinc oxide nanoparticle-coated socks compared to uncoated socks for the prevention of pitted keratolysis: a double-blinded, randomized, controlled trial study

BACKGROUND

Pitted keratolysis (PK) and bromodosis have negative impacts on the quality of life especially for military personnel. The antibacterial efficacy and safety of zinc oxide nanoparticles (ZnO-NPs) make them a suitable additive for textiles. We aim to establish the ability of ZnO-NP-coated socks to prevent PK and bromodosis in a real-life setting.

MATERIALS AND METHODS

A double-blinded, randomized, controlled trial was conducted in January 2019. Naval cadets assigned to a 14-day field training course were randomly allocated to either a ZnO-NP-coated or an uncoated-sock group. They completed questionnaires evaluating behavioral risk factors and self-assessed foot odor levels using a visual analogue scale (VAS); intervention-blinded dermatologists also performed foot examinations. They reassessed their odor levels and had their feet re-examined upon completion of the training course.

RESULTS

The 148 cadets enrolled for the study were allocated to two groups of 74 each. The ZnO-NP-coated sock participants demonstrated significantly less PK development than uncoated socks (P = 0.05). There was a reduction of the foot odor levels in both groups, as measured by the VAS, without statistical difference. However, the uncoated sock group experienced more foot odor with a significantly greater negative effect on their daily lives (P = 0.04) than the ZnO-NP-coated sock group.

CONCLUSIONS

ZnO-NP-coated socks proved their efficacy in inhibiting the development of PK for military personnel.

A Review on nanoparticles as a promising approach to improving diabetes mellitus

Diabetes mellitus (DM) is a chronic disease condition that causes multiple complications in various organs such as kidney, reproductive system, and liver. It is mainly characterized by high blood glucose, insulin secretion deficiency or insulin resistance. In conventional diabetes, medications of insulin production and increased insulin sensitivity usually cause undesirable side effects and lead to poor adherence and therapy failure. In addition to insulin and oral hypoglycemic agents, there are different healthy ways to treat diabetes. Nanoparticles (NPs) such as zinc oxide (ZnO) NPs, selenium (Se) NPs, magnesium oxide (MgO) NPs, Copper (Cu) NPs, and cerium oxide (CeO2) NPs play an important role in controlling diabetes. The results reviewed here presented antidiabetic activity of CeO2 NPs, Se NPs, ZnO NPs, Cu NPs, and MgO NPs with fewer side effects when compared to antioxidant enzymes, glucose use, or increased insulin sensitivity, as these showed complications with diabetes.

Titanium Dioxide, but Not Zinc Oxide, Nanoparticles Cause Severe Transcriptomic Alterations in T98G Human Glioblastoma Cells

Titanium dioxide and zinc oxide are two of the most widely used nanomaterials. We assessed the effects of noncytotoxic doses of both nanomaterials on T98G human glioblastoma cells by omic approaches. Surprisingly, no effects on the transcriptome of T98G cells was detected after exposure to 5 µg/mL of zinc oxide nanoparticles during 72 h. Conversely, the transcriptome of the cells exposed to 20 µg/mL of titanium dioxide nanoparticles during 72 h revealed alterations in lots of biological processes and molecular pathways. Alterations to the transcriptome suggests that exposure to titanium dioxide nanoparticles might, potentially, compromise the integrity of the blood brain barrier integrity and cause neuroinflammation. The latter issue was further confirmed phenotypically with a proteomic analysis and by recording the release of interleukin 8. Titanium dioxide also caused autophagy, which was demonstrated through the increase in the expression of the autophagy-related 3 and microtubule associated protein 1 light chain 3 alpha genes. The proteomic analysis revealed that titanium dioxide nanoparticles might have anticancerigen properties by downregulating genes involved in the detoxication of anthracyclines. A risk assessment resulting from titanium dioxide exposure, focusing on the central nervous system as a potential target of toxicity, is necessary.

Curcumin Nanoformulations with Metal Oxide Nanomaterials for Biomedical Applications

In the past few decades, curcumin, a natural polyphenolic phytochemical, has been studied for treating a wide variety of diseases. It has shown promising results as a potential curative agent for a variety of diseases. However, its inherent limitations, such as poor aqueous solubility, poor absorbability, fast metabolic rate, and quick elimination from the body, have limited its application beyond preclinical studies. A huge number of studies have been made to address the issues of curcumin and to maximally utilize its potentials. Many review articles have tried to assess and summarize different nanocarriers, especially organic nanocarriers, for nanoformulations with curcumin. Nevertheless, few exclusive reviews on the progress in nanoformulation of curcumin with inorganic nanomaterials have been made. In this review, we present an exclusive summary of the progress in nanoformulation of curcumin with metal oxide nanoparticles. The beneficial feature of the metal oxide nanoparticles used in the curcumin nanoformulation, the different approaches followed in formulating curcumin with the metal oxides, and the corresponding results, protective effect of curcumin from different metal oxide caused toxicities, and concluding remarks are presented in the review.

More serious autophagy can be induced by ZnO nanoparticles than single-walled carbon nanotubes in rat tracheal epithelial cells

Metal oxide nanoparticles and carbon nanoparticles, as common nanoparticles (NPs), can cause autophagy in certain cells, which will lead to biohealth risk issues. This study determined the difference in autophagy induced by zinc oxide nanoparticles (ZnO NPs) and single-walled carbon nanotubes (SWCNTs) in respiratory epithelial cells. ICP-OES results showed that NPs uptake as well as the intercellular contents of particles affected cytotoxicity in a dose-dependent manner. ZnO NPs-30 nm had a distinct green dot structure representing autophagy, the SWCNTs exposure group had a few green light spots at a concentration of 10 μg/L. The ROS content of the ZnO NP-30 nm exposure group had the greatest increase at a concentration of 1000 μg/L, which was 2.5 times higher than that of the control, the SWCNTs exposure group showed a 2.2-fold increase. A slight downregulation of p-mTOR was detected, and the ZnO NPs-30 nm treatment group had the significant downregulation rate. The gene and protein expression levels of Beclin-1 and LC3B were upregulated as the exposure concentration increased. The protein expression of Beclin-1 and LC3B in the 1000 μg/L ZnO NPs-30 nm exposure group were 5.21 times and 4.12 times that of the control, respectively. The mRNA expression of Beclin-1 and LC3B in the 1000 μg/L ZnO NPs-30 nm exposure group were 5.04 times and 3.61 times that of the control, respectively. At any concentration, the effect of ZnO NPs-30 nm was greater than that of the SWCNTs. Interaction and crosstalk analysis showed that exposure to ZnO NPs-30 nm caused autophagy through the aggregation of undegraded autophagosomes, whereas SWCNTs exposure induced diminished intercellular oxidative stress to inhibit autophagy. Therefore, this study demonstrated that the effects of autophagy induced by ZnO NPs-30 nm and SWCNTs were different. The health risks of ZnO-30 nm NPs are higher than those of SWCNTs.

ZnO/SiO2 core/shell nanowires for capturing CpG rich single-stranded DNAs

Atomic layer deposition (ALD) is capable of providing an ultrathin layer on high-aspect ratio structures with good conformality and tunable film properties. In this research, we modified the surface of ZnO nanowires through ALD for the fabrication of a ZnO/SiO2 (core/shell) nanowire microfluidic device which we utilized for the capture of CpG-rich single-stranded DNAs (ssDNA). Structural changes of the nanowires while varying the number of ALD cycles were evaluated by statistical analysis and their relationship with the capture efficiency was investigated. We hypothesized that finding the optimum number of ALD cycles would be crucial to ensure adequate coating for successful tuning to the desired surface properties, besides promoting a sufficient trapping region with optimal spacing size for capturing the ssDNAs as the biomolecules traverse through the dispersed nanowires. Using the optimal condition, we achieved high capture efficiency of ssDNAs (86.7%) which showed good potential to be further extended for the analysis of CpG sites in cancer-related genes. This finding is beneficial to the future design of core/shell nanowires for capturing ssDNAs in biomedical applications.

Antimicrobial efficacy of silver nanoparticles against Candida albicans: A systematic review protocol

INTRODUCTION

Denture-induced stomatitis is one form of candidiasis. It is characterised as inflammation and erythema of the oral mucosa underneath the denture-bearing areas and clinically classified into three types according to severity. Denture hygiene, appropriate mouth rinses and the use of antifungal therapy are commonly used to treat the condition, but new technologies are emerging that may assist in its treatment.

AIM

The aim of this systematic review is to determine if silver nanoparticles inhibit the growth of Candida Albicans when included in acrylic dentures and in different denture liners.

METHODOLOGY

A protocol was developed and published on PROSPERO (Registration No: CRD42019145542) and with the institutional ethics committee (Registration No: BM20/4/1). The protocol includes all aspects of a systematic review namely: selection criteria, search strategy, selection methods using predetermined eligibility criteria, data collection, data extraction, critical appraisal of included studies, and the intended statistical analyses such as calculating risk ratios (RR) for dichotomous outcomes and presented at 95% confidence intervals, a meta-analysis, if possible or a narrative report as needed.

EXPECTED RESULTS

With rigorous inclusion criteria set and databases identified for searching, appropriate clinical and laboratory studies may be obtained but the results and its interpretation and translation into clinical practice may be a challenge as these depend on the quality of the research.

Dynamics of water conveying zinc oxide through divergent-convergent channels with the effect of nanoparticles shape when Joule dissipation are significant

AIM OF STUDY

The shape effects of nanoparticles are very significant in fluid flow and heat transfer. In this paper, we discuss the effects of nanoparticles shape in nanofluid flow between divergent-convergent channels theoretically. In this present study, various shapes of nanoparticles, namely sphere, column and lamina in zinc oxide-water nanofluid are used. The effect of the magnetic field and joule dissipation are also considered.

RESEARCH METHODOLOGY

The system of nonlinear partial differential equations (PDEs) is converted into ordinary differential equations (ODES). The analytical solutions are successfully obtained and compared with numerical solutions. The Homotopy perturbation method and NDsolve method are used to compare analytical and numerical results respectively.

CONCLUSION

The results show that the lamina shape nanoparticles have higher performance in temperature disturbance and rate of heat transfer as compared to other shapes of nanoparticles.

SnO2-Doped ZnO/Reduced Graphene Oxide Nanocomposites: Synthesis, Characterization, and Improved Anticancer Activity via Oxidative Stress Pathway

BACKGROUND

Therapeutic selectivity and drug resistance are critical issues in cancer therapy. Currently, zinc oxide nanoparticles (ZnO NPs) hold considerable promise to tackle this problem due to their tunable physicochemical properties. This work was designed to prepare SnO2-doped ZnO NPs/reduced graphene oxide nanocomposites (SnO2-ZnO/rGO NCs) with enhanced anticancer activity and better biocompatibility than those of pure ZnO NPs.

MATERIALS AND METHODS

Pure ZnO NPs, SnO2-doped ZnO (SnO2-ZnO) NPs, and SnO2-ZnO/rGO NCs were prepared via a facile hydrothermal method. Prepared samples were characterized by field emission transmission electron microscopy (FETEM), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), ultraviolet-visible (UV-VIS) spectrometer, and dynamic light scattering (DLS) techniques. Selectivity and anticancer activity of prepared samples were assessed in human breast cancer (MCF-7) and human normal breast epithelial (MCF10A) cells. Possible mechanisms of anticancer activity of prepared samples were explored through oxidative stress pathway.

RESULTS

XRD spectra of SnO2-ZnO/rGO NCs confirmed the formation of single-phase of hexagonal wurtzite ZnO. High resolution TEM and SEM mapping showed homogenous distribution of SnO2 and rGO in ZnO NPs with high quality lattice fringes without any distortion. Band gap energy of SnO2-ZnO/rGO NCs was lower compared to SnO2-ZnO NPs and pure ZnO NPs. The SnO2-ZnO/rGO NCs exhibited significantly higher anticancer activity against MCF-7 cancer cells than those of SnO2-ZnO NPs and ZnO NPs. The SnO2-ZnO/rGO NCs induced apoptotic response through the upregulation of caspase-3 gene and depletion of mitochondrial membrane potential. Mechanistic study indicated that SnO2-ZnO/rGO NCs kill cancer cells through oxidative stress pathway. Moreover, biocompatibility of SnO2-ZnO/rGO NCs was also higher against normal breast epithelial (MCF10A cells) in comparison to SnO2-ZnO NPs and ZnO NPs.

CONCLUSION

SnO2-ZnO/rGO NCs showed enhanced anticancer activity and better biocompatibility than SnO2-ZnO NPs and pure ZnO NPs. This work suggested a new approach to improve the selectivity and anticancer activity of ZnO NPs. Studies on antitumor activity of SnO2-ZnO/rGO NCs in animal models are further warranted.

Interaction of Ras Binding Domain (RBD) by chemotherapeutic zinc oxide nanoparticles: Progress towards RAS pathway protein interference

Zinc oxide (ZnO) NP is considered as a nanoscale chemotherapeutic. Thus, the drug delivery of this inorganic NP is of considerable importance. Ras mutations are common in cancer and the activation of this signaling pathway is a hallmark in carcinoma, melanoma and many other aggressive malignancies. Thus, here we examined the binding and delivery of Ras binding domain (RBD), a model cancer-relevant protein and effector of Ras by ZnO NP. Shifts in zeta potential in water, PBS, DMEM and DMEM supplemented with FBS supported NP interaction to RBD. Fluorescence quenching of the NP was concentration-dependent for RBD, Stern-Volmer analysis of this data was used to estimate binding strength which was significant for ZnO-RBD (Kd < 10-5). ZnO NP interaction to RBD was further confirmed by pull-down assay demonstrated by SDS-PAGE analysis. The ability of ZnO NP to inhibit 3-D tumor spheroid was demonstrated in HeLa cell spheroids-the ZnO NP breaking apart these structures revealing a significant (>50%) zone of killing as shown by light and fluorescence microscopy after intra-vital staining. ZnO 100 nm was superior to ZnO 14 nm in terms of anticancer activity. When bound to ZnO NP, the anticancer activity of RBD was enhanced. These data indicate the potential diagnostic application or therapeutic activity of RBD-NP complexes in vivo which demands further investigation.

Zinc oxide nanoparticles: A comprehensive review on its synthesis, anticancer and drug delivery applications as well as health risks

In recent years, zinc oxide nanoparticles (ZnONPs) emerged as an excellent candidate in the field of optical, electrical, food packaging and particularly in biomedical research. ZnONPs show cancer cell specific toxicity via the pH-dependent (low pH) dissolution into Zn²⁺ ions, which generate reactive oxygen species and induce cytotoxicity in cancer cells. Further, ZnONPs have also been used as an effective carrier for the targeted delivery of several anticancer drugs into tumor cells. The increasing focus on ZnONPs resulted in the development of various synthesis approaches including chemical, pHysical, and green or biological for the manufacturing of ZnONPs. In this article, at first we have discussed the various synthesis methods of ZnONPs and secondly its biomedical applications. We have extensively reviewed the anticancer mechanism of ZnONPs on different types of cancers considering its size, shape and surface charge dependent cytotoxicity. Photoirradiation with UV light or NIR laser further increase its anticancer activity via synergistic chemo-photodynamic effect. The drug delivery applications of ZnONPs with special emphasis on drug loading mechanism, stimuli-responsive controlled release and therapeutic effects have also been discussed in this review. Finally, its side effects to vital body organs with mechanism via different exposure routes, the future direction of the ZnONPs research and application are also discussed.